[PATCH 2/2] lockdep: print lock name for lockdep_init_error

From: tom . leiming
Date: Thu Nov 17 2011 - 00:35:08 EST


From: Ming Lei <tom.leiming@xxxxxxxxx>

This patch prints the name of the lock which is acquired
before lockdep_init is called, so that user can easily find
which lock trigged the lockdep init error warning.

This patch also removes the lockdep_init_error message
of "Arch code didn't call lockdep_init() early enough?" since
lockdep_init is called in arch independent code now.

Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
---
kernel/lockdep.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 4e7e672..8141317 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -430,6 +430,7 @@ unsigned int max_lockdep_depth;
* about it later on, in lockdep_info().
*/
static int lockdep_init_error;
+static const char *lock_init_error;
static unsigned long lockdep_init_trace_data[20];
static struct stack_trace lockdep_init_trace = {
.max_entries = ARRAY_SIZE(lockdep_init_trace_data),
@@ -651,6 +652,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
if (unlikely(!lockdep_initialized)) {
lockdep_init();
lockdep_init_error = 1;
+ lock_init_error = lock->name;
save_stack_trace(&lockdep_init_trace);
}
#endif
@@ -3965,7 +3967,8 @@ void __init lockdep_info(void)

#ifdef CONFIG_DEBUG_LOCKDEP
if (lockdep_init_error) {
- printk("WARNING: lockdep init error! Arch code didn't call lockdep_init() early enough?\n");
+ printk("WARNING: lockdep init error! lock-%s was acquired"
+ "before lockdep_init\n", lock_init_error);
printk("Call stack leading to lockdep invocation was:\n");
print_stack_trace(&lockdep_init_trace, 0);
}
--
1.7.5.4

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